After barely surviving a brutal attack by a sadistic serial killer, crime boss Jang Dong-su is left humiliated. Determined to catch the killer known as K, he forms an uneasy alliance with Jung Tae-seok, a relentless and incorruptible detective who often disrupts his illegal business. However, while Jang Dong-su wants K dead, Jung Tae-suk is determined to bring him to justice. With a deal in place—whoever finds K first will decide his fate—the hunt begins, blurring the lines between crime and law.
A young woman with the ability to see mysterious red connections between lovers discovers her secret gift is no longer unique when special glasses granting similar powers appear on the black market.
Kim Hye-in has to transfer to Cheongdam International High School after witnessing a murder. She crosses paths with Baek Je-na, a bully who happens to be connected to the case.
